Metformin for low milk supply in PCOS mothers

Lisa Marasco–the ICBLC who is possibly the first researcher to examine the role of PCOS in low milk supply–has found evidence that Metformin can help with low milk supply in mothers with PCOS. The La Leche League has an excellent article by Marasco available on their web site (Marasco is an LLLI leader, as well as a lactation consultant).

Marasco suggests that anecdotal evidence shows a boost in milk production for low-supply moms with PCOS. She acknowledges that large-scale studies and high-quality research on this do not yet exist; however, in the absence of other good options, it may be worth trying. Marasco advocates using Metformin throughout the pregnancy and during breastfeeding.

Thomas Hale, the leading authority on the safety of drugs in breastfeeding mothers, has studied Metformin and concluded that it is quite safe. His assessment can be found here (warning: it’s pretty technical). Essentially, Hale found that the levels of Metformin in breastmilk were low, and that no adverse effects on the infants were reported.

He does point out, however, that “since metformin is largely excreted via the kidneys, particular caution should be exercised where the infant renal function is low or compromised (e.g. in premature neonates, or in rare cases of renal failure).” This doesn’t mean that no breastfeeding mother of a preemie should take Metformin; rather, it means that your doctor should consult with your child’s pediatrician and make the decision carefully. Since breastfeeding is beneficial, especially for premature babies, being able to produce more milk may benefit the infant enough to be worth the risk. Kidney function should be carefully monitored, though.

You may also be interested in this study, which examined infants whose mothers took Metformin over the course of their first six months of life. No differences in development or illnesses were found.

Finally, this page from Kellymom has a good list of links about PCOS and breastfeeding, including links to info about Metformin. (How much do I love Kellymom? A whole lot, that’s how much.)

Ultimately, my feeling on this matter is that it’s worth a shot. Metformin, which is a first-line treatment for PCOS, has a lot of benefits for PCOS sufferers; it can improve regularity of cycles and reduce other symptoms. I find it plausible that Met might make some differences to the hormonal balance that promote milk supply. Of course, not all patients find Metformin easy to tolerate; it often has significant GI side effects. Talk to your doctor about prescribing you the name brand (Glucophage) if that is true for you and adjusting your diet doesn’t help. Some PCOS ladies have reported that the generic has more side effects for them than the name brand.

That said, I took Met before I got pregnant with my son (and for the first trimester), and I had almost zero side effects. It regulated my cycle almost immediately and I conceived my son in the second month of trying. As a result, I’m a believer in Met’s ability to affect hormones for the better, which means that if I were going to have more children, I’d be taking it throughout the pregnancy and while breastfeeding.